Place the eggs in a saucepan and cover with cold water. Heat on the stove until boiling, then turn down to medium high and boil the eggs for 8 minutes. After 8 minutes drain the eggs and run them under cold water. Peel the eggs and chop them up in a bowl.
Grate the apple and the radish then fold into some kitchen paper. Squeeze gently to remove any excess water and then add to the bowl with the egg, along with the chopped dill.
Add the vinegar, mayonnaise and Greek yogurt to the eggs and stir gently to combine. Season with salt and pepper to taste. Serve on top of rye bread.